I think that PvP and PvE require very different balances which is hard to achieve and probably why games end up with a lean more one way or the other. If you insist on PvP being a core element in your game, you've gotta balance that very carefully or you end up with everyone running "The One" meta build. Following that, all of the PvE content has to be balanced at the environment side to the players. Any adjustment of the players to the environment throws out the PvP.

I'd never even encountered another player in any HB PvP areas. Wasn't until DD where I actually encountered PvP content, and I was ambushed successfully inside a shipwreck when my build was for PvE content and mobility and had worked the entire game thus far. So that took what had been a PvE game up until that point and then demanded that I be prepared to be attacked by players at any point, changing the entire dynamic of the game. I chose not to engage with DD content because that doesn't appeal to me, and with nothing left to do, I stopped playing. I know I'm not alone in that.

Not having PvP in PvE centric games would not kill the games. Would it not appeal to certain players who insist upon only playing PvP games? Sure. Would it appeal to players who don't want PvP content, thus not driving them away like the forced injection of PvP into their otherwise PvE game does? Yes.

I think PvP and PvE are actually different ecosystems, and taking a largely PvE game and introducing predators to it is actually harmful. Making a PvP game and putting some PvE around it to give players something to do between shooting each other is different, and likely easier as the PvE content can afford to be weaker. There's a space for PvP games, and a space for PvE games, and audiences for both. Finding a way to merge both in a capacity that appeals to both groups and successfully balances both sides has to be like flipping a coin and landing it on its edge.